I'm 18 years old guy but my height 5 feet 4 inch and weight is 48 kilogram only. so i feel shy. now what can i do to quicken my growth?

Nothing specific: Keep active & a healthy diet but don't expect to grow taller.At 18 most males growth centers have closed making increased height unlikely.If you want to know for sure an x-ray of your wrist & hand can be analysed for bone maturity & tell if the growth centers remain open to new growth.

Height: Boys usually have their main growth spurt in the mid-teens. Some may have a small second growth spurt after 18, but it depends on your family history. Most of the time your height velocity (how quickly you increase your height) is genetically determined. Eat healthy foods and exercise regularly, but you really can't change your height.